Browse Prior Art Database

Generating Italic Characters in CRT Displays

IP.com Disclosure Number: IPCOM000081026D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Ling, GC: AUTHOR

Abstract

Fig. 1 illustrates the path of an electron beam across the face of a cathode-ray tube (CRT) screen together with the current waveforms for the main vertical deflection yoke as a function of time, and for the main horizontal yoke as a function of time. Fig. 2 illustrates the "wiggle scan" technique, in which higher frequency vertical modulations are superimposed on a normal horizontal and vertical modulations by the use of an auxiliary vertical yoke. The current waveform in the main horizontal yoke in proportion to the current waveform in the auxiliary vertical yoke are shown in Fig. 2, with the time increment shown for the main horizontal yoke being equal to one of the increments for the main horizontal yoke in Fig. 1.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Generating Italic Characters in CRT Displays

Fig. 1 illustrates the path of an electron beam across the face of a cathode- ray tube (CRT) screen together with the current waveforms for the main vertical deflection yoke as a function of time, and for the main horizontal yoke as a function of time. Fig. 2 illustrates the "wiggle scan" technique, in which higher frequency vertical modulations are superimposed on a normal horizontal and vertical modulations by the use of an auxiliary vertical yoke. The current waveform in the main horizontal yoke in proportion to the current waveform in the auxiliary vertical yoke are shown in Fig. 2, with the time increment shown for the main horizontal yoke being equal to one of the increments for the main horizontal yoke in Fig. 1.

Fig. 3 illustrates video information as displayed when it is synchronized by the main and auxiliary vertical yokes and by the main horizontal yoke driven simultaneously, as shown by the waveform in Figs. 1 and 2. Fig. 4 shows the result as italicized characters which is produced when an auxiliary horizontal yoke is added and energized, as shown by the current waveforms i(v) for vertical and i(h) for horizontal. The waveforms for the vertical auxiliary yoke and the horizontal auxiliary yokes are shown in Fig. 4.

Fig. 5 illustrates the general case for the "wiggle scan" method, where italicized characters with a slant Theta having an offset Delta S(h) in the horizontal direction and a difference in height Delta S(y) in the vertical and horizontal yokes using waveforms i(y) and i(h), as shown. It...